U.S. Pat. Nos. 4,276,718 and 4,276,719 disclose methods and apparatus for effectively and efficiently applying contact herbicides to undesired plant growth to effect destruction thereof. While the structures and methods disclosed therein are emminently suited for their intended purpose, it is desirable under some circumstances to more positively insure that the herbicide when applied is in its maximum effective form. Conventional contact herbicides that are applied, such as ROUNDUP by Monsanto, are neutralized when brought into contact with certain foreign substances, such as clay. Additionally, some of such contact herbicides are more effective when caused to foam or froth just prior to application to weeds to be killed. Further in some horticultural applications positive prevention of contact with desired plants must be provided. According to the present invention, all these factors are taken into account in providing a simple and reliable method and apparatus for applying contact herbicides to plants in as effective a manner as practical.
According to one aspect of the method according to the present invention, a portable liquid applicator device is utilized. The device includes a container having a first, closed end and a second end with an opening therein; a wiping structure mounted in the container adjacent, but spaced from the open second end; and a liquid applicator structure with a fibrous exterior portion for holding liquid herbicide, insertable into and withdrawal from the container through the opening in the second end, and having a handle. The following method steps are practiced: (a) Liquid contact herbicide is disposed within the container so that it is partially filled with liquid, below the level of the wiping structure and, (b) the liquid applicator structure is inserted through the opening in the container second end to generally immerse a portion of the liquid applicator structure fibrous exterior portion in liquid herbicide, with the handle sticking outwardly from the container so that the handle never touches the herbicide. (c) The liquid applicator structure is partially removed, with herbicide held thereby, from the container by pulling on the handle to partially withdraw it as the fibrous exterior portion thereof is being wiped by the wiping structure, to a point just short of the end of travel of the liquid applicator structure with respect to the wiping structure. (d) The liquid applicator structure is then reinserted into the container to provide a reverse wiping of the fibrous exterior but so that the fibrous exterior of the liquid applicator structure does not become substantially immersed in liquid herbicide within the container, and (e) the liquid applicator structure is re-withdrawn from the container through the open second end thereof by pulling on the handle and completely removing the liquid applicator structure from the container, with frothed (foamed) herbicide held by the fibrous exterior portion. Then (f) the applicator structure fibrous exterior portion is touched to plants that are to be desirably destroyed so that herbicide is transferred from the structure to the plants, and (g) steps (b) through (f), if necessary, are occasionally repeated until desired plant destruction is completed, or until more liquid herbicide must be disposed in the container. The action between the fibrous exterior portion of the liquid applicator structure and the wiping structure during the back-and-forth relative movement therebetween effects frothing of the herbicide, rendering it more effective when plants are touched by the herbicide.
The liquid applicator device is constructed, according to the present invention, so that the wiping structure is properly positioned between the container second end and the volume of liquid herbicide within the container, so that the desired frothing action can occur without substantial re-immersion of the fibrous exterior portion of the liquid applicator structure in the liquid herbicide bath within the container. The wiping structure preferably comprises a ring having an opening diameter slightly smaller than the outside diameter of the fibrous exterior portion of the liquid applicator structure, which structure preferably comprises a conventional paint roller. One or more drainage holes are provided in the wiping ring to allow the herbicide that is wiped off thereby to drain back into the container.
According to another aspect of the method of the present invention, it is desirable to insure that no formed particles, such as clay particles, enter the container as it is being carried about by the user with the liquid applicator structure withdrawn. Of course it is also desirable to latch the liquid applicator structure in place within the container in sealing relationship with the container second end opening when the herbicide applicator is not being utilized, but is merely being transported or stored. To this end, a capping structure is provided operatively attached to the container so that it may be moved from a position spaced from the container second end opening and allowing access by the liquid applicator structure thereto, to a position in closing and sealing engagement with the opening. The cap is then secured in place when the liquid applicator device is withdrawn, and is removed prior to reinsertion of the liquid applicator device. Also, a latching arrangement may be associated with the cap and/or its attaching means to the container, to engage an opening in the liquid applicator structure handle to latch the liquid applicator structure in place in closing and sealing engagement with the second end opening. The structure facilitating this aspect of the method according to the present invention preferably comprises a strap connected at one end thereof to the container, and connected adjacent the other end thereof to a cap. A portion of the other end of the strap past the cap is free to facilitate grasping thereof to effect movement of the cap from its closing and sealing position. A hook is preferably provided on the cap for receipt by a hook-receiving opening in the handle, which latches the handle in place when the hook and opening are in operative engagement.
According to other aspects of the present invention, the liquid applicator device preferably is formed as a roller having a relatively rigid core with a fibrous covering thereon (i.e. a conventional paint roller). The handle includes one end thereof shaped so as to tightly frictionally engage the interior of the paint roller core. The handle is forced into place originally, and when the roller wears out, is contaminated, or the like, the roller may be removed from the handle and the handle reinserted into frictional engagement with a new roller core interior. Additionally a carrying strap is provided which facilitates carrying of the container with the second end thereof pointing upwardly, and the interior of the first end of the container is formed with a locating portion for positively aligning the roller in the container. The cap and the closing and sealing structure associated with the roller handle, are formed in simple yet effective manner. Positive prevention of roller contact with desired plants in horticultrual applications is provided by a bent handle extension keyed to a semi-circular guard.
It is the primary object of the present invention to provide a method and device for simple yet effective application of contact herbicide to undesired plant growth. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.